I'm trying to find out if the Allwinner A10 developer(s) intend to go further (eg. Allwinner A3x) or if the Allwinner A10 is the end of the road (based on project roadmap not available project hardware).

I have seen many release projects where developers are focused on a single solution which is perfectly fine. However.... it is useful to know if there are future plans for a project in order to either embrace it's limitation or move on to other solutions.

A10 is not the planned end of the road. The project roadmap depends on Debian's future support of Allwinner boards as well as having the hardware here to develop with. Right now, it appears Debian supports A10 and A20, A3.x is not available.